JPH02129977A - Gas laser oscillator - Google Patents

Abstract

PURPOSE:To achieve compactness and efficiency by providing a discharge electrode of an insulation plate at the negative side in a laser gas room and by providing a conductive metal layer to a discharge electrode mounting surface of this insulation plate. CONSTITUTION:A screening wall 12A and a screening wall 12B are provided at the lower surface of left and right edges of an insulation plate 7B between a blower 4 and between a cooler 5, respectively, the area between these screening walls 12A and 12B is cooled by the cooler 5, thus becoming one part of flow path of laser gas to be circulated in the direction marked by arrows 3A and 3B. Thus, the upper and lower surfaces of the insulation plate 7B become the same pressure surfaced of laser gas pressure within an external wind cavity 1, thus enabling the plate thickness to be thin. As a result, it is possible not only to drop frequency of voltage applied between discharge electrodes 6A and 6B at a high-frequency power supply but also to maintain withstand voltage with the screening plates 12A and 12B even using a material whose dielectric constant is not high, thus making it easy to select the material of the insulation plate 7B and to make the width narrow. It achieves compactness and efficiency.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention particularly relates to a gas laser oscillator that oscillates by applying a high three-frequency voltage between discharge electrodes.

(Prior Art) In FIG. 4, which shows an example of a conventional gas laser oscillator using a high-frequency power source, an external wind tunnel 1 made of a steel plate with a rectangular cross section has an interior made of a steel plate with a U-shaped cross section that communicates with the outside air. A wind tunnel 2 is provided, and an insulating plate 7A made of quartz glass or the like is airtightly attached to the upper center of the outer wind tunnel 1, and the same insulating plate 7B is airtightly attached to the upper part of the inner wind tunnel 2, so that there is no air between these two wind tunnels. Laser gas sealed at a pressure of about 601 orr is circulated clockwise as shown by arrows 3A and 3B by a blower 4 on the lower left side and cooled by a cooler 5 on the lower right side.

Further, a discharge electrode plate 6A is attached to the upper center surface of the insulating plate 7A, and a discharge electrode plate 6B is attached to the lower center surface of the insulating plate 7B, and the discharge electrode 6A is connected to one side of the high frequency power source 8, and the discharge electrode 6B is grounded. Insulating plate 7A, 7 connected to the other side of the high frequency power supply
A discharge is caused between the inner surfaces of B to generate laser light 10 in a direction perpendicular to the plane of the paper.

(Problem to be Solved by the Invention) In the high-frequency gas laser oscillator configured in this manner, the insulating plates 6^, 6B are made of a thick material that can withstand the pressure difference between the inside and outside, and the voltage applied between the discharge electrodes 6A, 68 is increased accordingly. A high voltage is also required. Then, the required creepage distance between the discharge electrode 6B and the internal wind tunnel 2 increases, and the width of the insulating plate 7B also increases, so not only does the internal wind tunnel 2 become larger, but also the material of the insulating plates 7A and 7B becomes more dielectric in terms of voltage resistance. I need something with a high rate.

Furthermore, as shown in FIG. 5, discharge occurs in the minute gap G formed between the insulating plate 7B and the discharge electrode 6B, reducing the efficiency of the laser oscillator.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to obtain a small and efficient high-frequency discharge gas laser oscillator.

[Structure of the invention]

(Means and Effects for Solving the Problems) The present invention provides a pair of parallel insulators in which low-pressure laser gas is circulated on opposing surfaces, electrode plates connected to a high-frequency power source are attached to the outer surfaces, and both sides are attached to the wind tunnel wall. In a high-frequency gas laser oscillator in which a laser gas is excited by a discharge electrode between plates, at least one discharge electrode is provided in a wind tunnel, and a conductive metal layer is provided on the discharge electrode mounting surface of at least one insulating plate. This is a high-frequency discharge gas laser oscillator with a small external size and increased oscillator efficiency.

(Embodiment) Hereinafter, one embodiment of the high-frequency discharge gas laser oscillator of the present invention will be described with reference to the drawings. However, parts that overlap with Figure 4 are omitted.

In FIG. 1, a steel plate partition wall 12A is provided between the blowers 4 and a partition wall 12B between the coolers 5 on the lower surface of the left and right ends of the insulating plate 7B. It forms part of a flow path for laser gas that is cooled by a blower 5 and circulated clockwise as shown by arrows 3A and 3B.

Further, as shown in FIG. 2, which is a partially enlarged view, on the surface of the insulating plate 7B that is in contact with the discharge electrode 6B, a sprayed aluminum layer 11 is formed in advance, and the discharge electrode 6B is separated from the discharge electrode 6B by a minute gap 12.
They are in contact with each other through a minute projection 6B1 formed between them, and the discharge electrode 6B is provided with a through hole (not shown) through which cooling water flows.

In the gas laser oscillator having such a configuration, the upper and lower surfaces of the insulating plate IB are both at the same pressure surface of the laser gas pressure in the external wind tunnel 1, so that the plate thickness can be reduced. Then, not only can the frequency of the voltage applied between the discharge electrodes 6A and 6B by the high frequency power source 8 be lowered (for example, from the conventional several tens of MH2 to 100 MHz to several MH2), but also it is possible to reduce the frequency of the voltage applied between the discharge electrodes 6A and 6B. Also partition plates 12A, 12B
Since the withstand voltage can be maintained, the material for the insulating plate 7B can be easily selected, and the width can be made narrower, so the external wind tunnel 1 can be made smaller.

Similarly, by lowering the frequency of the high-frequency voltage applied between the discharge electrodes 6A and 68, the wiring actance from the power source to the electrodes is reduced, which not only reduces voltage drop but also facilitates wiring.

Furthermore, since there is no discharge between the insulating plate 7B and the discharge electrode 68, the efficiency of the laser oscillator can be improved.

In the above embodiment, an outer wall may be provided outside the discharge electrode 6A to cover the insulating plate IA with a gap therebetween, so that the outer surfaces of the discharge electrode 6A and the insulating plate 7A are also placed in the laser gas. Thereby, the width of the insulating plate 7A can be narrowed, and the outer shape of the laser oscillator can be further reduced in size.

FIG. 3 shows another embodiment of the high frequency discharge gas laser oscillator of the present invention.

In FIG. 3, the grounding example of the laser power source is connected directly to the sprayed aluminum layer 11, with the cooling section 13 mounted on the outside thereof. The cooling unit 13 is provided with through holes (not shown) through which cooling water flows.

[Effects of the Invention] As described above, according to the present invention, a discharge electrode plate to which a high frequency voltage is applied is attached to the outer surface of a pair of parallel insulating plates, and a low-pressure laser gas circulated between the insulating plates is excited. In a high-frequency gas laser oscillator that generates a discharge, the discharge electrode of at least one side of the insulating plate is provided in the laser gas chamber, and a conductive metal layer is provided on the discharge electrode mounting surface of at least one side of the insulating plate, so that it can be compact. It is possible to obtain an efficient high-frequency discharge gas laser oscillator.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing one embodiment of the high-frequency discharge gas laser oscillator of the present invention, FIG. 2 is a partially enlarged view of FIG. 1, and FIG. 3 is another embodiment of the high-frequency discharge gas laser oscillator of the present invention. FIG. 4 is a diagram showing an example of a conventional single-frequency discharge gas laser oscillator, and FIG. 5 is a partially enlarged view of FIG. 4. 1...External wind tunnel 6A, 613...Discharge electrodes 7A, 7B...Insulating plate 8...High frequency power source 11...Metal sprayed layer (8733) Agent: Yoshiaki Inomata, patent attorney (and 1 other person) ) Figure Figure

Claims (1)

[Scope of Claims] A discharge electrode plate to which a high frequency voltage is applied is closely attached to the center of the outer surface of a pair of parallel insulating plates whose outer peripheries are airtightly attached to the wind tunnel wall, and between the discharge electrode plates In a gas laser oscillator that excites low-pressure laser gas flowing between the pair of insulating plates with a high-frequency discharge, at least one side of the pair of insulating plates on which the discharge electrode is attached is provided in the wind tunnel in which the laser gas is sealed; A gas laser oscillator characterized in that a conductive layer is formed on the discharge electrode mounting surface of at least one side of a pair of insulating plates.